Vitamin D deficit link to Covid-19 severity ‘considerable’

Much to gain by recommending supplementation for all, says expert

People have “nothing to lose”, and much to gain, by taking vitamin D supplements as protection during the Covid-19 pandemic, according to a new paper by Irish and UK scientists.

Evidence linking vitamin D deficiency with severity of Covid-19 disease is "circumstantial but considerable", according to the paper co-authored by professor of medical gerontology at Trinity College Dublin, Rose Anne Kenny.

“There seems nothing to lose and potentially much to gain by recommending vitamin D supplementation for all, making it clear that this is to help ensure immune health and not solely for bone and muscle health,” she says.

“This should be mandated for prescription for vulnerable adults and children, such as those in care, prisons, or other institutions where people are likely to be inside for much of the time during the summer.”


Prof Kenny says new US research indicates that virus patients are four times less likely to require admission to ICU if they have normal levels of vitamin D.

But in addition, for the first time the research suggests people with good levels of the vitamin may be less likely to become infected, according to Prof Kenny.

Change recommendations

Last May, she called on the Government to immediately change recommendations by advising people to take vitamin D supplements during the pandemic.

While no change was made to public health advice, Prof Kenny has sent the new position paper prepared for the Royal Society of Data Analytics in the UK to the Irish authorities.

Almost half the Irish population is deficient in vitamin D, which is produced in the skin from UVB sunlight exposure and also available in foods such as oily fish and cheese.


But with winter approaching and the result of randomised controlled trials unlikely to be ready before the pandemic ends, Prof Kenny says people urgently need to ensure they get enough vitamin D through supplementation.

Vitamin D is one of the treatments used by US president Donald Trump, who is currently being treated for the disease.

Prof Kenny says people should be taking 800 IU (international units) of vitamin D daily, twice the recommended level in England, Scotland and Wales.

In August, the Lancet said it would seem “uncontroversial” to enthusiastically promote regular intake of the vitamin, adding “there is a chance” this might reduce the impact of the virus in populations where vitamin D deficiency is prevalent.

Paul Cullen

Paul Cullen

Paul Cullen is Health Editor of The Irish Times